Friday, November 11, 2011

NGC 7008 by eye and camera

Adam Block/Mount Lemmon SkyCenter/University of Arizona
We continue to be completely clouded out here in the Old Pueblo (Tucson), prohibiting any observational astronomy day or night.  At least we are in the bright moon period so I am not missing too much.  Just this week, Adam Block published an image of NGC 7008 that was captured at the Mount Lemmon SkyCenter using the 32 inch Schulman telescope. It is quite a beautiful planetary nebula, with a pair of bright (relatively) colorful stars to the south of the nebula.  Looking at the nebula, I immediately recognized the object as one that I had sketched earlier this year.  At left is the image and below is my sketch.  Together they illustrate the difference between what can be seen with the eye versus a camera.  In both the image and sketch, North is up and West is to the right.  I completed my sketch on the night of July 2nd 2011, using my 12 inch LX200 SCT and a 10mm Pentax XW eyepiece yielding a magnification of 305X.

This nebula resides in the constellation of Cygnus the swan, approximately 2800 light years away.  It was discovered by William Herschel in 1787 and is sometimes known popularly as the "fetus nebula."  This nebula resulted from a brief phase near the end of life of the central star when it was shedding off its outer layers.  This process resulted in a much cooler star, known as a white dwarf.  Incredibly, that single star has created a nebula that is about one light year in diameter!

You can see some of the other examples of the world-class imaging being done at the Mount Lemmon SkyCenter by Adam Block and guests of the programs by visiting this web page.

No comments:

Post a Comment